feat: add timestamps plugin to manage created_at and updated_at fields

Introduced a new timestamps plugin that allows the addition of `created_at` and `updated_at` fields to specified entities. Included tests to verify functionality, ensuring timestamps are correctly set on entity creation and updates. Updated the plugin index to export the new timestamps functionality.

app/src/plugins/data/timestamp.plugin.spec.ts

@@ -0,0 +1,74 @@
+import { describe, test, expect, beforeAll, afterAll } from "bun:test";
+import { timestamps } from "./timestamps.plugin";
+import { em, entity, text } from "bknd";
+import { createApp } from "core/test/utils";
+import { disableConsoleLog, enableConsoleLog } from "core/utils/test";
+
+beforeAll(() => disableConsoleLog());
+afterAll(enableConsoleLog);
+
+describe("timestamps plugin", () => {
+   test("should ignore if no or invalid entities are provided", async () => {
+      const app = createApp({
+         options: {
+            plugins: [timestamps({ entities: [] })],
+         },
+      });
+      await app.build();
+      expect(app.em.entities.map((e) => e.name)).toEqual([]);
+
+      {
+         const app = createApp({
+            options: {
+               plugins: [timestamps({ entities: ["posts"] })],
+            },
+         });
+         await app.build();
+         expect(app.em.entities.map((e) => e.name)).toEqual([]);
+      }
+   });
+
+   test("should add timestamps to the specified entities", async () => {
+      const app = createApp({
+         config: {
+            data: em({
+               posts: entity("posts", {
+                  title: text(),
+               }),
+            }).toJSON(),
+         },
+         options: {
+            plugins: [timestamps({ entities: ["posts", "invalid"] })],
+         },
+      });
+      await app.build();
+      expect(app.em.entities.map((e) => e.name)).toEqual(["posts"]);
+      expect(app.em.entity("posts")?.fields.map((f) => f.name)).toEqual([
+         "id",
+         "title",
+         "created_at",
+         "updated_at",
+      ]);
+
+      // insert
+      const mutator = app.em.mutator(app.em.entity("posts"));
+      const { data } = await mutator.insertOne({ title: "Hello" });
+      expect(data.created_at).toBeDefined();
+      expect(data.updated_at).toBeDefined();
+      expect(data.created_at).toBeInstanceOf(Date);
+      expect(data.updated_at).toBeInstanceOf(Date);
+      const diff = data.created_at.getTime() - data.updated_at.getTime();
+      expect(diff).toBeLessThan(10);
+      expect(diff).toBeGreaterThan(-1);
+
+      // update (set updated_at to null, otherwise it's too fast to test)
+      await app.em.connection.kysely
+         .updateTable("posts")
+         .set({ updated_at: null })
+         .where("id", "=", data.id)
+         .execute();
+      const { data: updatedData } = await mutator.updateOne(data.id, { title: "Hello 2" });
+      expect(updatedData.updated_at).toBeDefined();
+      expect(updatedData.updated_at).toBeInstanceOf(Date);
+   });
+});

app/src/plugins/data/timestamps.plugin.ts

@@ -0,0 +1,86 @@
+import { type App, type AppPlugin, em, entity, datetime, DatabaseEvents } from "bknd";
+import { $console } from "bknd/utils";
+
+export type TimestampsPluginOptions = {
+   entities: string[];
+   setUpdatedOnCreate?: boolean;
+};
+
+/**
+ * This plugin adds `created_at` and `updated_at` fields to the specified entities.
+ * Add it to your plugins in `bknd.config.ts` like this:
+ *
+ * ```ts
+ * export default {
+ *    plugins: [timestamps({ entities: ["posts"] })],
+ * }
+ * ```
+ */
+export function timestamps({
+   entities = [],
+   setUpdatedOnCreate = true,
+}: TimestampsPluginOptions): AppPlugin {
+   return (app: App) => ({
+      name: "timestamps",
+      schema: () => {
+         if (entities.length === 0) {
+            $console.warn("No entities specified for timestamps plugin");
+            return;
+         }
+
+         const appEntities = app.em.entities.map((e) => e.name);
+
+         return em(
+            Object.fromEntries(
+               entities
+                  .filter((e) => appEntities.includes(e))
+                  .map((e) => [
+                     e,
+                     entity(e, {
+                        created_at: datetime(),
+                        updated_at: datetime(),
+                     }),
+                  ]),
+            ),
+         );
+      },
+      onBuilt: async () => {
+         app.emgr.onEvent(
+            DatabaseEvents.MutatorInsertBefore,
+            (event) => {
+               const { entity, data } = event.params;
+               if (entities.includes(entity.name)) {
+                  return {
+                     ...data,
+                     created_at: new Date(),
+                     updated_at: setUpdatedOnCreate ? new Date() : null,
+                  };
+               }
+               return data;
+            },
+            {
+               mode: "sync",
+               id: "bknd-timestamps",
+            },
+         );
+
+         app.emgr.onEvent(
+            DatabaseEvents.MutatorUpdateBefore,
+            async (event) => {
+               const { entity, data } = event.params;
+               if (entities.includes(entity.name)) {
+                  return {
+                     ...data,
+                     updated_at: new Date(),
+                  };
+               }
+               return data;
+            },
+            {
+               mode: "sync",
+               id: "bknd-timestamps",
+            },
+         );
+      },
+   });
+}

app/src/plugins/index.ts

@@ -7,3 +7,4 @@ export { showRoutes, type ShowRoutesOptions } from "./dev/show-routes.plugin";
 export { syncConfig, type SyncConfigOptions } from "./dev/sync-config.plugin";
 export { syncTypes, type SyncTypesOptions } from "./dev/sync-types.plugin";
 export { syncSecrets, type SyncSecretsOptions } from "./dev/sync-secrets.plugin";
+export { timestamps, type TimestampsPluginOptions } from "./data/timestamps.plugin";